Heavy Fuel Oil Product

ABSTRACT

A heavy fuel oil product consists essentially of a hydroprocessed product of a high-sulfur-content feedstock that is at least one of A) a feedstock that is non-compliant with ISO 8217: 2017; B) a feedstock that is of non-merchantable quality as a residual marine fuel oil, and C) an intermediate product obtained by hydroprocessing a feedstock that is non-compliant with ISO 8217: 2017 so that the intermediate product is compliant with ISO 8217: 2017 but has a sulfur content of from 0.5 wt. % or more, the hydroprocessed product having a final sulfur content (ISO 14596 or ISO 8754) of less than 0.5 wt. %.

BACKGROUND

Large ocean-going ships have relied upon heavy fuel oil (HFO) since the 1960s. This inexpensive and widely available fuel source provided the impetus for the rapid growth of the international shipping industry during that time. The HFO market has been a reliable way for refiners to utilize the viscous, high-contaminant waste products of many crude oil refining processes. Because of this, the HFO composition is highly variable and can include any combination of atmospheric, vacuum, and visbreak residues, cycle oils, slurry oil, heavy gas oils, polycyclic aromatic hydrocarbons, reclaimed motor oils, etc., and may be cut with a small volumes of kerosene, diesel, or other diluents to meet the desired product specifications, particularly for viscosity.

Because HFOs contain high levels of contaminants, and because of the rapid growth of the international shipping industry, emissions from ocean-going ships burning HFO are a significant component of global air pollution. With most developed nations now working to reduce emissions worldwide, regulations have been put in place in a variety of industries; however the refining industry has been an area of considerable focus.

In 1973 the MARPOL Convention was adopted at the International Maritime Organization (IMO). The International Convention for the Prevention of Pollution from Ships (MARPOL) is the main international convention covering prevention of pollution of the marine environment by ships from operational or accidental causes. The Convention currently includes six technical Annexes. Special Areas with strict controls on operational discharges are included in most Annexes.

In 2005 MARPOL Annex VI set limits on SOx and NOx from ship exhausts and prohibited deliberate emissions of ozone depleting substances. Designated emission control areas set more stringent standards for SOx, NOx and particulate matter. On Jan. 1, 2020, the global limit for sulfur in fuel oil used on board ships will be capped at 0.5% m/m (mass by mass). This is a drastic reduction from the previous limit of 3.5% m/m. Furthermore, IMO Regulation 14 set a maximum sulfur content of 0.1% m/m for fuel oils used inside an Emission Control Area (ECA) after Jan. 1, 2015. As of the date of this filing, the established ECAS include the Baltic Sea area, the North Sea area, the North American area, and the United States Caribbean Sea area.

These regulatory conventions have brought about an urgent need for low sulfur (<0.5% m/m) and ultra-low sulfur (<0.1% m/m) fuel oils for marine use. While a variety of solutions have been proposed to meet the need for low and ultra-low sulfur fuels (renewable fuels, fuel blending, and a switch to liquified natural gas (LNG) or marine diesel), issues with supply, compatibility with existing equipment, and quality of blends necessitate that hydroprocessed fuel oils make up a larger proportion of the marine fuel oil market for 2020 and beyond. Accordingly, improvements are needed.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the disclosure, reference is now made to the following descriptions taken in conjunction with the accompanying FIGURE, in which:

FIG. 1 is a schematic of a hydroprocessing system for treating a high-sulfur-content feedstock showing the process flow in accordance with particular embodiments of the invention to form a high fuel oil product.

DETAILED DESCRIPTION

The present invention is directed to the production of a heavy fuel oil product that meets those regulatory conventions that are being imposed for the use of such heavy fuel oil as marine fuels with respect to sulfur content, as well as other requirements. This is achieved by treating a high-sulfur-content feedstock that has certain characteristics to form a heavy fuel oil having a low sulfur or ultra-low sulfur content. The feedstock may be a high-sulfur-content heavy fuel oil or other material that does not constitute a heavy fuel oil but that has a high sulfur content.

The high-sulfur-content heavy fuel oils include those residual-based fuel oils that are derived from process residues from crude oil refining. These are the fractions that do not boil or vaporize, even under vacuum conditions. Such heavy fuel or residual-based fuel oil materials may have a high asphaltene content that may range from 3 wt. % to 20 wt. %. Non-limiting examples of such heavy fuel oils include atmospheric, vacuum, and visbreak residues, cycle oils, slurry oils, heavy gas oils, polycyclic aromatic hydrocarbons, reclaimed motor oil, etc. These materials may be cut with small amounts (e.g., less than 20% by volume) of cutter oil, kerosene, diesel, or other diluents to meet the desire product specifications, particularly viscosity.

The high-sulfur-content feedstock material may be a heavy fuel oil, as described above, with or without any diluent, or may be a non-heavy fuel oil material. These materials may be renewable or non-renewable materials. Non-heavy fuel oil materials may include renewable materials or those derived from non-petroleum or biological sources. Non-limiting examples of such renewable, biological or non-petroleum materials are those described in U.S. Pat. No. 9,096,804, which is incorporated herein by reference for all purposes, including those hydroprocessing techniques described therein.

The sulfur content (ISO 14596 or ISO 8754) of the feedstock must be at least equal to or greater than 0.5 wt. %. In certain embodiments, the sulfur content (ISO 14596 or ISO 8754) may be equal to or greater than 1 wt. %, 2 wt. %, 3 wt. %, 4 wt. %, 5 wt. %, 6 wt. %, 7 wt. %, 8 wt. %, 9 wt. %, and 10 wt. %. In particular instances, the feedstock may have a sulfur content of from at least, equal to, and/or between any two of 0.5 wt. %, 0.6 wt. %, 0.7 wt. %, 0.8 wt. %, 0.9 wt. %, 1 wt. %, 2 wt. %, 3 wt. %, 4 wt. %, 5 wt. %, 6 wt. %, 7 wt. %, 8 wt. %, 9 wt. %, and 10 wt. %.

It should be noted in the description, if a numerical value or range is presented, each numerical value should be read once as modified by the term “about” (unless already expressly so modified), and then read again as not so modified unless otherwise indicated in context. Also, in the description, it should be understood that an amount range listed or described as being useful, suitable, or the like, is intended that any and every value within the range, including the end points, is to be considered as having been stated. For example, “a range of from 1 to 10” is to be read as indicating each and every possible number along the continuum between about 1 and about 10. Thus, even if specific points within the range, or even no point within the range, are explicitly identified or refer to, it is to be understood that the inventors appreciate and understands that any and all points within the range are to be considered to have been specified, and that inventors possesses the entire range and all points within the range.

In one particular embodiment, to produce the heavy fuel oil product the high-sulfur-content feedstock that is treated is a feedstock that is non-compliant with ISO 8217: 2017, the provisions of which are hereby incorporated herein by reference. ISO 8217: 2017 is a regulatory standard for residual marine fuel oils with respect to their bulk properties, but excludes the concentration levels of environmental contaminants. Such environmental contaminants include SO_(x), NO_(x), and particulate materials that are produced upon combustion. Thus, in the present invention, the feedstock used to produce the heavy fuel product may be a feedstock that is non-compliant with ISO 8217: 2017 with respect to its bulk properties. Such non-compliance may result from the feedstock material characteristics failing to meet any one or more of the bulk property characteristics set forth ISO 8217: 2017, but excluding any environmental contaminant limits, particularly sulfur contaminant limits.

The ISO 8217: 2017 compliant characteristics include a maximum kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s, a maximum density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³, a calculated carbon aromaticity index (CCAI) of from 780 to 870, and a flash point (ISO 2719) of no lower than 60.0° C. Other characteristics of ISO 8217: 2017 include a maximum total sediment-aged (ISO 10307-2) of 0.10 wt. %, a maximum carbon residue—micro method (ISO 10370) between the range of 18.00 wt. % and 20.00 wt. %, and a maximum aluminum plus silicon content (ISO10478) of 60 mg/kg.

Thus, the feedstock used for producing the HFO product may be any high-sulfur-content feedstock, such as a heavy fuel oil feedstock, that is outside (either below or above) any one or more of the above-listed ranges or values or other non-listed ranges or values with respect to ISO 8217: 2017.

In another embodiment, the HFO product is produced from a high-sulfur-content feedstock that is of non-merchantable quality as a residual marine fuel oil. As used herein, the expression “non-merchantable quality as a residual marine fuel oil” is to be construed to mean that the feedstock material does not meet the level of quality for a residual marine fuel oil so that the fuel is not fit for the purpose of serving as a residual fuel source for a marine ship and cannot be commercially sold as a residual marine fuel oil and is not fungible (or compatible) with heavy or residual marine bunker fuel. Such feedstocks that are of a non-merchantable quality as a residual marine fuel oil are not stable, compatible or miscible with other residual heavy marine fuels. In certain instances, this non-merchantable quality can be determined by using a cleanliness test according to ASTM D4740 Static Stability Spot Testing, which provides a rating of 1, 2, 3, 4, or 5. Those materials that rate a 1 or 2 are considered clean and merchantable as a residual marine fuel, while materials with a rating of 3 or more are considered to be of unacceptable cleanness and not of merchantable quality for use as a residual marine fuel oil. In the present invention, the feedstock that is of a non-merchantable quality as a residual marine fuel oil would thus have an ASTM D4740 Static Stability Spot Testing rating of 3 or more.

In still another embodiment, a heavy fuel oil product is produced from a high-sulfur-content feedstock that constitutes an intermediate product obtained by hydroprocessing a feedstock that is non-compliant with ISO 8217: 2017 so that the intermediate product is compliant with ISO 8217: 2017 but has a sulfur content of from 0.5 wt. % or more. The intermediate product is then hydroprocessed further so that the hydroprocessed product has a final sulfur content (ISO 14596 or ISO 8754) of less than 0.5 wt. %.

Any of the above-described high-sulfur-content feedstocks may be blended with a diluent to form a blended feedstock. The blended feedstock is then hydroprocessed to form the final heavy fuel oil product having low or ultra-low sulfur content. The diluents may be compliant or non-compliant with ISO 8217: 2017. Furthermore, the blended feedstock with the added diluent may be compliant or non-compliant with ISO 8217: 2017.

The diluents used to form the blended feedstocks from the above-described high-sulfur-content feedstocks may include, but are not limited to kerosene, diesel, gas oil, marine gas oil (MGO), marine diesel oil (MDO), light liquid hydrocarbons, distillates, vacuum gas oil (VGO), renewable oils and fuels, biodiesel, alcohols, methanol, ethanol, synthetic hydrocarbons and oils, Fischer-Tropsch derived hydrocarbons and oils, refinery residues, fluid catalytic cracker (FCC) materials, FCC slurry oil, FCC cycle oil, pyrolysis gas oil, cracked light gas oil, cracked heavy gas oil, light cycle oil, heavy cycle oil, thermally cracked residues, coker heavy distillate, bitumen, de-asphalted heavy oil, visbreaker residue, slop oils, asphaltene oils, recycled motor oils, lube oil, aromatic extracts, crude oils, previously hydroprocessed materials, etc. With respect to previously hydroprocessed materials, these may include a portion of the hydroprocessed product from the high-sulfur content feedstock that is then recycled and combined with fresh high-sulfur content to be treated.

FIG. 1 shows a schematic of a generalized system 10 to produce a low or ultra-low sulfur heavy fuel oil product from high-sulfur-content feedstocks. Any one or more of the high-sulfur-content feedstocks, with or without added diluents, described above may be used with the system 10. The system 10 includes a hydroprocessing reactor 12 formed from a reactor vessel 14 that houses the various internal components of the reactor 12, including one or more hydroprocessing catalyst beds 16 containing a hydroprocessing catalyst. Such hydroprocessing catalysts are well known in the art. The configuration of the reactor and amount and type of catalyst used in the reactor may be that that provides sufficient conversion and removal of sulfur from the feedstock.

The reactor 12 is provided with an inlet for introducing a feed stream 18 of the high-sulfur-content feedstock into the interior of the reactor vessel 14. A hydrogen-containing gas 20 that is fluidly coupled to a hydrogen gas source is combined with the feed stream and introduced into the inlet of the reactor 12. The feedstock and hydrogen contact the hydroprocessing catalyst where the feedstock and hydrogen react. Sulfur compounds in the high-sulfur-content feedstock are removed from the feedstock and converted to H₂S. Nitrogen, as well as other metals, may also be removed from the feedstock during the hydroprocessing reaction. The reactor may be altered in configuration and in number to accommodate the specifications required of the product, given a specific feed. To achieve the desired product specifications, the addition of one or more additional reactors and/or reaction zones may be used.

Hydroprocessed reaction products 22 are removed from the reactor 12 through an outlet. The reaction products 22 may be cooled in a heat exchanger unit 24 and delivered to a high pressure separator unit 26. Hydrogen and other light gases (e.g., methane, ethane, etc.) 28 may be removed from the high pressure separator 26. If desired, removed hydrogen gas may be recycled and combined with the hydrogen feed 20. Separated liquid products 30 from high pressure separator may be delivered to a further separation unit 32, which may include a stripping unit. Residual gases 34, such as H₂S and other gases such as nitrogen, hydrogen, carbon dioxide, steam, and light hydrocarbons, are removed from the product stream 30 in the separator unit 32. Liquid byproducts 36 may also be removed. The liquid byproducts may be those C₄-C₂₀ hydrocarbons that may be formed during the hydroprocessing reaction.

The product stream 38 constitutes the hydroprocessed product that forms all or a portion of the low or ultra-low sulfur heavy fuel oil product. The heavy fuel oil product may have a final sulfur content (ISO 14596 or ISO 8754) of less than 0.5 wt. %, 0.4 wt. %, 0.3 wt. %, 0.2 wt. %, or 0.1 wt. %. In addition to having low or ultra-low sulfur content, the final heavy fuel oil product may also be compliant with ISO 8217: 2017 and/or be of a merchantable quality as a residual marine fuel oil.

In certain instances, the hydroprocessed product 38 constitutes the entire low or ultra-low sulfur heavy fuel oil product with no diluents added. In other instances, the hydroprocessed product may be blended with one or more diluents to from the final low or ultra-low sulfur heavy fuel oil product. The diluent may include but not be limited to kerosene, diesel, gas oil, marine gas oil (MGO), marine diesel oil (MDO), light liquid hydrocarbons, distillates, vacuum gas oil (VGO), renewable oils and fuels, biodiesel, alcohols, methanol, ethanol, synthetic hydrocarbons and oils, Fischer-Tropsch derived hydrocarbons and oils, refinery residues, fluid catalytic cracker (FCC) materials, FCC slurry oil, FCC cycle oil, pyrolysis gas oil, cracked light gas oil, cracked heavy gas oil, light cycle oil, heavy cycle oil, thermally cracked residues, coker heavy distillate, bitumen, de-asphalted heavy oil, visbreaker residue, slop oils, asphaltene oils, recycled motor oils, lube oil, aromatic extracts, crude oils, previously hydroprocessed materials, etc.

In cases where a diluent is used to form a final blended product that forms the final low or ultra-low sulfur heavy fuel oil product, the diluent of the blended product may be compliant or non-compliant with ISO 8217: 2017, while the final blended product is compliant with ISO 8217: 2017. In other cases, the hydroprocessed product may be non-compliant with ISO 8217: 2017 and the diluent may be compliant or non-compliant with ISO 8217: 2017, while the final blended product may be compliant with ISO 8217: 2017.

Additionally, the hydroprocessed product may have a sulfur content (ISO 14596 or ISO 8754) of less than 0.5 wt. % but greater than one of 0.4 wt. %, 0.3 wt. %, 0.2 wt. %, or 0.1 wt. %, but may be combined with a diluent to form a blended product that forms the final heavy fuel oil product that has a sulfur content (ISO 14596 or ISO 8754) of less than one of 0.4 wt. %, 0.3 wt. %, 0.2 wt. %, or 0.1 wt. %.

In certain instances, the hydroprocessed product may be of non-merchantable quality as a residual marine fuel oil, but may be combined with a diluent to form a blended product that is of a merchantable quality as a residual marine fuel oil.

The final heavy fuel oil product, blended or non-blended with any diluent, may also have any one or more or all of the characteristics of a maximum kinematic viscosity at 50° C. (ISO 3104) between the range from 180 mm²/s to 700 mm²/s, a maximum density at 15° C. (ISO 3675) between the range of 991.0 kg/m³ to 1010.0 kg/m³, a calculated carbon aromaticity index (CCAI) of from 780 to 870, and a flash point (ISO 2719) of no lower than 60.0° C., a maximum total sediment-aged (ISO 10307-2) of 0.10 wt. %, a maximum carbon residue—micro method (ISO 10370) between the range of 18.00 wt. % and 20.00 wt. %, and a maximum aluminum plus silicon content (ISO10478) of 60 mg/kg.

When combined with a diluents to form a blended product, the hydroprocessed product may be used in an amount of at least, equal to, and/or between any two of 75%, 7%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, and 100% by volume of the blended product. The diluent of such blended product may be used in an amount of at least, equal to, and/or between any two of 0% to 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, and 25% by volume of the blended product.

In addition to diluents, the final heavy fuel oil product may contain other additives and ingredients. These may include such things as detergents, pour point depressants, viscosity or lubricity modifiers, stabilizers, etc. These may be present in amounts of from 5 wt. %, 4 wt. %, 3 wt. %, 2 wt. %, 1 wt. %, 0.5 wt. % or less by total weigh of the final heavy fuel oil product, blended or non-blended with any diluent.

While the invention has been shown in only some of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes and modifications without departing from the scope of the invention. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention. 

We claim:
 1. A heavy fuel oil product comprising: a hydroprocessed product of a high-sulfur-content feedstock that is at least one of A) a feedstock that is non-compliant with ISO 8217: 2017; B) a feedstock that is of non-merchantable quality as a residual marine fuel oil, and C) an intermediate product obtained by hydroprocessing a feedstock that is non-compliant with ISO 8217: 2017 so that the intermediate product is compliant with ISO 8217: 2017 but has a sulfur content of from 0.5 wt. % or more, the hydroprocessed product having a final sulfur content (ISO 14596 or ISO 8754) of less than 0.5 wt. %.
 2. The product of claim 1, wherein: the high-sulfur-content feedstock is derived from at least one of renewable and nonrenewable feedstocks.
 3. The product of claim 1, wherein: the feedstock is A.
 4. The product of claim 1, wherein: the feedstock is B.
 5. The product of claim 1, wherein: the feedstock is C.
 6. The product of claim 1, wherein: the feedstock is A and B.
 7. The product of claim 1, wherein: the hydroprocessed product has a sulfur content (ISO 14596 or ISO 8754) of less than 0.1 wt. %.
 8. The product of claim 1, wherein: the high-sulfur-content feedstock is A, wherein A is an intermediate product obtained by hydroprocessing a feedstock that is compliant with ISO 8217: 2017 so that the intermediate product is non-compliant with ISO 8217:
 2017. 9. The product of claim 8, wherein: the hydroprocessed product has a sulfur content (ISO 14596 or ISO 8754) of less than 0.1 wt. %.
 10. The product of claim 9, wherein: the feedstock is C and the hydroprocessed product has a sulfur content (ISO 14596 or ISO 8754) of less than 0.1 wt. %.
 11. The product of claim 1, wherein the feedstock is any one of A, B, and C, wherein A, B, and C are intermediate products obtained by hydroprocessing a feedstock that is blended with a diluent to form a blended feedstock.
 12. The product of claim 11, wherein: the diluent is non-compliant with ISO 8217:
 2017. 13. The product of claim 12, wherein: the blended feedstock is non-compliant with ISO 8217:
 2017. 14. The product of claim 12, wherein: the blended feedstock is compliant with ISO 8217:
 2017. 15. The product of claim 11, wherein: the diluent is compliant with ISO 8217:
 2017. 16. The product of claim 15, wherein: the blended feedstock is non-compliant with ISO 8217:
 2017. 17. The product of claim 15, wherein: the blended feedstock is compliant with ISO 8217:
 2017. 18. The product of claim 1, further comprising: a diluent that is blended with the hydroprocessed product.
 19. The product of claim 1, further comprising: a diluent that is blended with the hydroprocessed product to form a blended product that is compliant ISO 8217: 2017 and/or has a sulfur content (ISO 14596 or ISO 8754) of less than 0.1 wt. %.
 20. The product of claim 19, wherein: the diluent is selected from at least one of diesel, fuel oil, gas oil, cutter oil, renewable oil, renewable fuel, synthetic oil, refinery residues, and lube oils. 